A number of different signaling protocols are used in an Internet Protocol Multimedia Subsystem (IMS) network, such as Session Initiation Protocol (SIP) and Diameter. Further, the signaling associated with a session involves many different nodes. When troubleshooting in an IMS network it is desirable to identify all messages associated with a certain session. When considering the SIP signaling, it is possible to look at a parameter referred to as Call-ID. By detecting the same Call-ID value in different signaling messages it is possible to conclude that these messages belong to the same session. However, there are no mechanisms today which enable a troubleshooter to find the corresponding Diameter (or other non SIP protocol) messages for that specific session in an easy way.
There are also issues, from a troubleshooting perspective, when entities acting as B2BUAs (Back to Back User Agent) are involved. Example of B2BUAs are application servers, border gateways etc. The B2BUAs change the Call-ID value when they “forward/proxy” a SIP message, i.e. they start a new SIP dialogue. This implies that messages belonging to the same session (but different dialogs) will have different Call-ID values and it is therefore not possible to identify all messages belonging to the same session.